# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0

import subprocess
from typing import Any, Optional

from loggers import get_logger

from utils.native_path_leases import child_env_without_native_path_secret
from utils.subprocess_compat import (
    windows_hidden_subprocess_kwargs as _windows_hidden_subprocess_kwargs,
)

logger = get_logger(__name__)


def _parse_smi_value(raw: str):
    raw = raw.strip()
    if not raw or raw == "[N/A]":
        return None
    try:
        return float(raw)
    except (ValueError, TypeError):
        return None


def _build_gpu_metrics(
    vram_used_mb, vram_total_mb, power_draw, power_limit, **extra
) -> dict[str, Any]:
    return {
        **extra,
        "vram_used_gb": round(vram_used_mb / 1024, 2) if vram_used_mb is not None else None,
        "vram_total_gb": round(vram_total_mb / 1024, 2) if vram_total_mb is not None else None,
        "vram_utilization_pct": round((vram_used_mb / vram_total_mb) * 100, 1)
        if vram_used_mb is not None and vram_total_mb and vram_total_mb > 0
        else None,
        "power_draw_w": power_draw,
        "power_limit_w": power_limit,
        "power_utilization_pct": round((power_draw / power_limit) * 100, 1)
        if power_draw is not None and power_limit and power_limit > 0
        else None,
    }


def _visible_ordinal_map(parent_visible_ids: Optional[list[int]]) -> Optional[dict[int, int]]:
    if parent_visible_ids is None:
        return None
    return {gpu_id: ordinal for ordinal, gpu_id in enumerate(parent_visible_ids)}


def get_physical_gpu_count() -> Optional[int]:
    """Return physical GPU count via nvidia-smi, or None on failure."""
    try:
        result = subprocess.run(
            ["nvidia-smi", "-L"],
            capture_output = True,
            text = True,
            timeout = 5,
            env = child_env_without_native_path_secret(),
            **_windows_hidden_subprocess_kwargs(),
        )
        if result.returncode == 0 and result.stdout.strip():
            return len(result.stdout.strip().splitlines())
        logger.warning(
            "nvidia-smi -L returned code %d; caller should fall back to torch",
            result.returncode,
        )
    except Exception as e:
        logger.warning("nvidia-smi -L failed: %s; caller should fall back to torch", e)
    return None


def get_primary_gpu_utilization() -> dict[str, Any]:
    try:
        result = subprocess.run(
            [
                "nvidia-smi",
                "--query-gpu=utilization.gpu,temperature.gpu,"
                "memory.used,memory.total,power.draw,power.limit",
                "--format=csv,noheader,nounits",
            ],
            capture_output = True,
            text = True,
            timeout = 5,
            env = child_env_without_native_path_secret(),
            **_windows_hidden_subprocess_kwargs(),
        )
    except (OSError, subprocess.TimeoutExpired) as e:
        logger.warning("nvidia-smi query failed in get_primary_gpu_utilization: %s", e)
        return {"available": False}
    if result.returncode != 0 or not result.stdout.strip():
        return {"available": False}

    first_line = result.stdout.strip().splitlines()[0]
    parts = [p.strip() for p in first_line.split(",")]
    if len(parts) < 6:
        return {"available": False}

    return _build_gpu_metrics(
        vram_used_mb = _parse_smi_value(parts[2]),
        vram_total_mb = _parse_smi_value(parts[3]),
        power_draw = _parse_smi_value(parts[4]),
        power_limit = _parse_smi_value(parts[5]),
        available = True,
        gpu_utilization_pct = _parse_smi_value(parts[0]),
        temperature_c = _parse_smi_value(parts[1]),
    )


def get_visible_gpu_utilization(
    parent_visible_ids: Optional[list[int]], parent_cuda_visible_devices: Optional[str] = None
) -> dict[str, Any]:
    # parent_visible_ids None (UUID/MIG mask): can't map nvidia-smi rows to
    # visible devices, so return empty rather than exposing all physical GPUs.
    if parent_visible_ids is None:
        return {
            "available": False,
            "backend_cuda_visible_devices": parent_cuda_visible_devices,
            "parent_visible_gpu_ids": [],
            "devices": [],
            "index_kind": "unresolved",
        }
    visible_ordinals = _visible_ordinal_map(parent_visible_ids)
    try:
        result = subprocess.run(
            [
                "nvidia-smi",
                "--query-gpu=index,utilization.gpu,temperature.gpu,"
                "memory.used,memory.total,power.draw,power.limit",
                "--format=csv,noheader,nounits",
            ],
            capture_output = True,
            text = True,
            timeout = 5,
            env = child_env_without_native_path_secret(),
            **_windows_hidden_subprocess_kwargs(),
        )
    except (OSError, subprocess.TimeoutExpired) as e:
        logger.warning("nvidia-smi query failed in get_visible_gpu_utilization: %s", e)
        return {
            "available": False,
            "backend_cuda_visible_devices": parent_cuda_visible_devices,
            "parent_visible_gpu_ids": parent_visible_ids or [],
            "devices": [],
            "index_kind": "physical",
        }
    if result.returncode != 0 or not result.stdout.strip():
        return {
            "available": False,
            "backend_cuda_visible_devices": parent_cuda_visible_devices,
            "parent_visible_gpu_ids": parent_visible_ids or [],
            "devices": [],
            "index_kind": "physical",
        }

    devices = []
    for line in result.stdout.strip().splitlines():
        parts = [p.strip() for p in line.split(",")]
        if len(parts) < 7:
            continue

        try:
            idx = int(parts[0])
        except (ValueError, TypeError):
            continue

        if visible_ordinals is not None and idx not in visible_ordinals:
            continue

        devices.append(
            _build_gpu_metrics(
                vram_used_mb = _parse_smi_value(parts[3]),
                vram_total_mb = _parse_smi_value(parts[4]),
                power_draw = _parse_smi_value(parts[5]),
                power_limit = _parse_smi_value(parts[6]),
                index = idx,
                index_kind = "physical",
                visible_ordinal = (
                    visible_ordinals[idx] if visible_ordinals is not None else len(devices)
                ),
                gpu_utilization_pct = _parse_smi_value(parts[1]),
                temperature_c = _parse_smi_value(parts[2]),
            )
        )

    return {
        "available": len(devices) > 0,
        "backend_cuda_visible_devices": parent_cuda_visible_devices,
        "parent_visible_gpu_ids": parent_visible_ids or [],
        "devices": devices,
        "index_kind": "physical",
    }


def get_backend_visible_gpu_info(
    parent_visible_ids: Optional[list[int]], backend_cuda_visible_devices: Optional[str]
) -> dict[str, Any]:
    # parent_visible_ids None (UUID/MIG mask): can't map nvidia-smi rows to
    # visible devices.
    if parent_visible_ids is None:
        return {
            "available": False,
            "backend_cuda_visible_devices": backend_cuda_visible_devices,
            "parent_visible_gpu_ids": [],
            "devices": [],
            "index_kind": "unresolved",
        }
    visible_ordinals = _visible_ordinal_map(parent_visible_ids)
    try:
        result = subprocess.run(
            [
                "nvidia-smi",
                "--query-gpu=index,name,memory.total",
                "--format=csv,noheader,nounits",
            ],
            capture_output = True,
            text = True,
            timeout = 10,
            env = child_env_without_native_path_secret(),
            **_windows_hidden_subprocess_kwargs(),
        )
    except (OSError, subprocess.TimeoutExpired) as e:
        logger.warning("nvidia-smi query failed in get_backend_visible_gpu_info: %s", e)
        return {
            "available": False,
            "backend_cuda_visible_devices": backend_cuda_visible_devices,
            "parent_visible_gpu_ids": parent_visible_ids or [],
            "devices": [],
            "index_kind": "physical",
        }
    if result.returncode != 0:
        return {
            "available": False,
            "backend_cuda_visible_devices": backend_cuda_visible_devices,
            "parent_visible_gpu_ids": parent_visible_ids or [],
            "devices": [],
            "index_kind": "physical",
        }

    devices = []
    for line in result.stdout.strip().splitlines():
        parts = [p.strip() for p in line.split(",")]
        if len(parts) < 3:
            continue
        try:
            idx = int(parts[0])
        except (ValueError, TypeError):
            continue
        if visible_ordinals is not None and idx not in visible_ordinals:
            continue
        # Rejoin in case the GPU name contains commas
        name = parts[1] if len(parts) == 3 else ", ".join(parts[1:-1])
        try:
            mem_total_mb = int(parts[-1])
        except (ValueError, TypeError):
            continue
        devices.append(
            {
                "index": idx,
                "index_kind": "physical",
                "visible_ordinal": (
                    visible_ordinals[idx] if visible_ordinals is not None else len(devices)
                ),
                "name": name,
                "memory_total_gb": round(mem_total_mb / 1024, 2),
            }
        )

    return {
        "available": len(devices) > 0,
        "backend_cuda_visible_devices": backend_cuda_visible_devices,
        "parent_visible_gpu_ids": parent_visible_ids or [],
        "devices": devices,
        "index_kind": "physical",
    }
